The aims of the proposed research are to elucidate the psychosocial factors critical to maintenance or relapse in self-quitting of smoking and to evaluate the outcomes of some prototypical ways by which smokers try to quit without the help of formal programs. The psychosocial factors to be examined will include stressful life events, perceived stress social support social network characteristics (e.g., interactions with other smokers) and coping strategies. The covariation (and interaction) of these factors with relapse or maintenance will be compared in four samples of subjects: New Years resolution quitters, participants in two different instruction manual programs, and an instruction manual plus four optional group sessions program. Results from previous work relating these psychosocial factors to clinic aided quitting will also be compared with the self-quitting data. Follow-up smoking status and some probes for the psychosocial factors will be obtained at one two three, six and twelve months after the initial quit attempt. Assessments will be carried out by telephone interview. Multivariate procedures, e.g., stepwise multiple regression, will be used to evaluate the relation of psychosocial factors to outcome. The reactivity of the assessment procedures will be experimentally evaluated by comparing groups which receive minimal assessment with those receiving the entire assessment battery. Both the outcomes and cost effectiveness of the four programs will be evaluated. It is expected that the programs providing more assistance (e.g. group sessions) will be more successful but less cost effective than programs providing minimal assistance.